Long-term cooling history of the Albertine Rift: new evidence from the western rift shoulder, D.R. Congo
Long-term cooling history of the Albertine Rift: new evidence from the western rift shoulder, D.R. Congo
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DOI：
10.1007/s00531-015-1146-6
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发表时间：
2016-09
影响因子：
2.3
通讯作者：
F. Bauer;F. Bauer;U. Glasmacher;U. Ring;R. Grobe;V. Mambo;Matthias Starz
中科院分区：
文献类型：
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作者：
F. Bauer;F. Bauer;U. Glasmacher;U. Ring;R. Grobe;V. Mambo;Matthias Starz
为了确定东非艾伯丁裂谷的长期景观演变，应用低温热年代学，并使用热历史建模限制冷却历史。结果表明：（1）“古老”的冷却年龄，主要有泥盆纪至石炭纪的磷灰石裂变径迹年龄、奥陶纪至志留纪的锆石（U-Th）/He年龄和侏罗纪至白垩纪的磷灰石（U-Th-Sm）/He年龄;（2）西裂谷肩的冷却历史较长，主要折返期在中古生代和古近纪至新近纪;（3）古生代和新近纪的侵蚀速率较低。这表明分析的样品在地壳最上层停留的时间很长，目前的地表在近地表位置已有数亿年的时间。磷灰石He冷却年龄和热历史模型表明，在侏罗纪至白垩纪的适度再加热。连同冷却年龄分布，一个可能的艾伯丁高压与一个明显的救济可以推断，可能是一个源区的刚果盆地。
To determine the long-term landscape evolution of the Albertine Rift in East Africa, low-temperature thermochronology was applied and the cooling history constrained using thermal history modelling. Acquired results reveal (1) “old” cooling ages, with predominantly Devonian to Carboniferous apatite fission-track ages, Ordovician to Silurian zircon (U–Th)/He ages and Jurassic to Cretaceous apatite (U–Th–Sm)/He ages; (2) protracted cooling histories of the western rift shoulder with major phases of exhumation in mid-Palaeozoic and Palaeogene to Neogene times; (3) low Palaeozoic and Neogene erosion rates. This indicates a long residence time of the analysed samples in the uppermost crust, with the current landscape surface at a near-surface position for hundreds of million years. Apatite He cooling ages and thermal history models indicate moderate reheating in Jurassic to Cretaceous times. Together with the cooling age distribution, a possible Albertine high with a distinct relief can be inferred that might have been a source area for the Congo Basin.